Engine fuel injector



Aug.V 9, 1938. J. w. Dow

ENGINE FUEL INJECTOR Filed July 21, 1957 Patented Aug. 9, 1938 UNITEDSTATES PATENT OFFICE alcanza ENGINE FUEL nvmcroa John W. Dow,` SiouxCity, Iowa sppliesunn Julysl, 1937. serial No. 154,904 s claims. (cl.ass-107.4)

- The invention relates to improvements in fuel injectors for engines ofthe Diesel type and it aims to provide a new and improved injector inwhich novel provision is made for retaining and heating the fuel fedfrom the fuel pump. and for moving this fuel in such manner that itshall become highly heated before discharge.

A further object is to provide a novel sectional construction which maybe 4readily assembled l0 without danger of fuel ports moving out ofconducting relation with each other. may be readily disassembled andcleaned, and may be easily reassembled without danger of disarrangingany parts. y Another object isto provide an improved injector in which ashoulder onthe plunger coacts with a shoulder in the cylinder in whichsaid plunger slides, in forming an expansible and contractible chamberwhich receives fuel upon ascent of the plunger and discharges the fuelupon Danying drawing'.

` `:lo rig. 1 ls averucal longlmdlnal sectional view.

through an injector. constructed in accordance with the inventiomtheplunger being shown in 'y completely lowered position.

Fig. 2 is a fragmentary view similar to the lower end of Fig. 1 butshowing the plunger raised.` Fig. 3 is an upper end view of acylindrical block in which a number of the fuel portsare formed.

Fig. 4 is a vertical sectional view on line l-l sooflig.

Fig. 5 is a lower end elevation of the block shown in Figs. 3 and 4.

Fig. 6 is an upper side elevation of a ring which abutsthe lower end ofthe above mentioned block, said ring being provided with fuel ports andwith an inverted conical central opening which `coacts with theextension on the lower end or the plunger.

Fig. 7 is a sectional view on line ii-i of Fig. ti. Fig. 8 is a lowerside elevation of the ring shown in Figs. 6 and 3.

Fig. Q is an upper end elevation of the cap which secures theaboveenlentiorled cylindrieaiI bloei-.t and ring to the cylinder ortubular casing oli the 565 injecter.

Fig. 10 is a lower end elevation of this cap.

Fig. 11 is a sectional view .on line. lI-II of Fig. 9. f A

A preferredconstruction has been illustrated and will be specificallydescribed, with the un- 5 derstanding however, that within the scope of'the invention as claimed. variations may be made.

Furthermore,- while such terms as "upper and lower" will be employed indescribing and c1aim ing the invention, it is to be understood that l0cylinder.

The lower section Il of the casing l2 is pro- 20' vided with an inlet ilvfor fuel supplied by means of a fuel pump (not shown). said inlet'orsome other suitable portion ofthe fuel supply means being provided withacheck valve Il. The casing section Il is also provided with a fuelsupply 25 port Il which extends in the present disclosure. from thecheck valve` I8 to the iowerendof said section. The upper section I3 ofthe casing Il is provided with a suitable drain Il'for any fuelleak- 30ing past the plunger 2|but to prevent excessive leakage, said plunger isprovided with grooves 22 which catch some of the oil, or sealing rings(not shpwn) could be employed.

The plunger 2| is raised by a suitable spring 2l 35l housed in the uppersection I3 of the casing I2, and is depressed by a rocker arm or thelike (not shown) operated inthe usual way from the engine crank shaft. Acylindrical block 24 is disposed at the lower 4 end of the casing I2,the upper end oi' said block being in contact with the lower end of saidcasing and being provided with an annular groove 25 which communicateswith the lower end of the port i9, no matter to what position the' block24 44s may be turned. The lower end of this block 24 is provided withany desired numberV of substantially radial grooves 26. Outerlongitudinaliy ports 2 are formed through the block 2li from the annulargroove 2E to the outer ends of the radial: grooves titi, and innerlongitudiuai 2&3 are termed in said block, the lower ends ai said parte2@ being in communication with inner ends of the grooves. 2t. The upperends the ports open through the upper enel et the se siderably less thanthe internal diameter of the casing section i4.

A ring 2| is disposed under the block 24, the upper side of said ringbeing in contact with the lower end of said block and -being providedwith an annular groove 22 communicating with the lower ends of the ports22. The ring 2| is formed with a central valve seat preferably in theform of an inverted conical opening 22 which corn-4 municates with thebore of the block 24, and

4 said ring is provided also with a suitable number of ports 24 whichextend from the groove 22 to the opening 22.

A capr is threaded or otherwise secured upon the lower end of the casingsection i4 and snugly contains the ring 2| and the block 24. thebottomof said cap being provided with fuel spray means 22 communicating withthe lower end of the opening 22. When threading the cap onto` the casingsection i4, it is not necessary that the ports 21 occupy anypredeterminedpositions in order to properly receive the fuel from thesupply port i2, due to the provision of the annular groove 22 in theupper end of the block 24. Similarly, it is not necessary that the ports24 occupy any particular positions to receive fuel from the ports 22, ashereinafter described, due to the provisionof the annular groove 22 inthe upper side of the ring 2|'. There is thus no danger of assemblingthe parts with any of the ports out of conducting relation with eachother.

.The plunger 2i is provided with a reduced extension 21 at its lowerend, said extension being slidable ini the bore 22 of the block 24 andhaving a valve portion preferably in the form of an inverted conicallower end 22 which seats in theiinverted conical opening 22 of the ring2| 'when the plunger is fully lowered. At the upper end of the extension21,' the plunger is provided with a downwardly facing shoulder 22 whichis cooperable with the shoulder 22 formed by the upper end of the block24, in forming an expansibleand contractible fuel chamber 42. Uponascent of the plunger 2| (see Fig. 2), Vfuel'enters the chamber 42' fromthe ports 22 of the block 24, being supplied to said ports 22 by meansof the port i2. groove 22, ports21 and'grooves 22. Upon descent of theplunger, the fuel from the chamber 42 is discharged through the ports22. through the ports 24, through the opening 22, and through the fuelspray means 22. All of the ports are of coursealways full of fuel andthe latter is therefore effectively heated. Moreover, by entering thechamber 42 in the manner above described, the fuel becomes stillfurtherheated in the tip of the injector, and the heating continues asthe fuel is discharged into the engine cylinders. The plunger 2| ofcourse rises during the compression strokes of the engine and some ofthe hot compressed air from the engine cylinder enters through the fuelspray means 22,

,coming in contact with some of the fuel andl also performing a heatingfunction, and atthe height of compression, or other suitable moment iaccording to the timing of the engine, the plunger descends, injecting acharge of fuel `and the hot A air which has entered under the plungerend 22,

into the cylinder. Y It will be seen from the foregoing that novel andlinexpensive provision has been made for carrying out the objects of theinvention, and while preferred details of construction have been shown,attention is again invited to the possi bility of making variationswithinthe scope of` the invention as claimed.

1. An engine fuel injector comprising an elongated cylinder the bore ofwhich is formed with a reduced lower end portion to provide anupwardlyfacing shoulder, s aid reduced bore portion having n inverted`conical lower end and the cylinder eing formed with fuel Vspray meanscommunicating with said inverted conical lower end of said reduced boreportion, said cylinder being provided with a port from said shoulder tosaid inverted conical lower end of said reduced bore portion and beingalso provided with a longitudlnal fuel supply port which discharges intotheflrst named port; and a plunger slidable in said bore of saidcylinder and having an extension slidable in said reduced bore portion,the lower end of said extension being of inverted conical form to seatin said inverted conical lower end of said reduced bore portion when theplunger is fully lowered. said plunger having a downwardly facingshoulder above said upwardly facing shoulder of said cylinder andcooperable therewith in forming an expansible and contractible fuelchamber which receives fuel from the upper end of said `first named portwhen the plunger ascends, the fuel being discharged from .said chamberthrough said first named port, 'throughsaid inverted conical lower endof said said block being disposed against the lower end of said tubularcasing, said block being provided with an outer longitudinal port andwith an inner longitudinal port, the lower ends of these ports being incommunication with each other, the upper end of said outer port being incommunication with said fuel supply port of said tubular casing, theupper end of said inner port being open at the upper end of Asaid blockbetween said central bore and the inner periphery of said tubularcasing; a ring having its upper side. disposed against the lower end ofsaid block, said ring having a central inverted conical openingcommunicating with said central bore, said ring being formed with a fuelport from its upper side to said inverted conical opening, the upper endof this port being in communication with the lower end of said innerport of said block; a cap secured to said lower end of said tubularcasing and containing said ring and said block, said cap having fuelspray means communicating with the lower end of said inverted conicalopening of said ring.v and a plunger slidable in said tubular casing andhaving a downward extension slidable in said bore of said block, thelower end of said extension' charged from said chamberthrough said innerport of said block, through said port and inverted conical opening ofsaid ring, and through said fuel spray means of said cap when saidplunger descends.

3. An engine fuel injector comprising a tubular casing having a fuelsupply port opening through its lower end; a cylindrical block having acentral bore of less diameter than the interior of said tubular casing,the upper end of said block being disposed against the lower end of saidtubular casing and having an annular groove communicating with said fuelsupply port, the lower end of said block being formed with substantiallyradial grooves, said block being provided with outer longitudinal portsextending from said annular groove to the outer ends of said radialgrooves and being provided also with inner longitudinal ports from theinner ends of said radial grooves to the 'upper end of the block, theupper ends of said inner ports being disposed between said bore of theblock and the inner periphery of said tubular casing; a ring having itsupper side disposed against the lower end of said block, said ringhaving an 'inverted conical central opening communicating with the lowerend of said bore of said, block, said ring being formed with ports fromits upper side to said inverted conical opening, the upper ends of theseports being in communication with said inner ports of said block; a capsecured to the spray means communicating with the lower end Y of saidinverted conical opening oi' said ring;

and a plunger slidable in said tubular casing and having a downwardextension slidable in said bore of said block, the lower end of saidextension being of inverted conical form to seat in said invertedconicalv opening of said ring when the plunger is fully lowered, saidplunger having a shoulder disposed over said block and cooperable withthe upper end of the latter in forming an expansible and contractiblefuel chamber which receives fuel from said inner ports of said blockwhen the plunger ascends, the fuel being discharged from said chamberthrough said inn'er ports of said block, through said ports and invertedconical opening of said ring, and through said fuel spray means of saidcap when said plunger descends.

4. An engine fuel injector comprising a tubular casing having a fuelsupply port opening through its lower end; a cylindrical block having acentral bore of less diameter than the interior of said tubular casing,the upper end of said block being disposed againstthe lower end of saidtubular casing and having an annular groove communicating with said fuelsupply port, the lower endof said block being formed with substantiallyradial grooves, said block being provided with outer longitudinal portsex;- tending from said annular groove to the outer ends of said radialgrooves and being provided also with inner longitudinal ports from thelnner ends of said .radial grooves to the upper end of the block, theupper ends of said inner ports being disposed between said bore of theblock and the inner periphery of said tubular casing; a ring having itsupper side disposed against the lower end of said block, said upper sideof said ring being provided with an annular groove d communicating withsaid inner ports of said said annular groove of said ring, said invertedconical opening being in communication with the lower end of said boreoi.' said block; a cap secured to the llower end of said tubular casingand containing said ring and said block, said cap having fuel spraymeans communicating with the lower end of said inverted conical openingof said ring; and a plunger slidable in said tubular casing and havingan 'extension slidable in said bore of said block, the lower end of saidextension being of inverted conical form to seat in said invertedconical opening of said ring when the plunger is fully lowered, saidplunger being provided with a shoulder'over said block and cooperablewith the upper end of the latter in forming an expansibleandcontractible fuel chamber which receives fuel from said inner ports ofsaid block when the plunger ascends, the fuel being discharged from saidchamber through said inner ports of said block, through said annulargroove, ports and inverted conical opening of said. ring', and throughsaid fuel spraymeans of saidl cap when said plunger descends.

5. An engine fuel injector comprising an elongated cylinder, the bore ofwhich is formed with a reduced lower end portion to provide an upwardlyfacing shoulder, said reduced bore portion having a valve seat at itslower end and the cylinder being formed with `fuel spray means openingthrough said valve seat, said cylinder being provided with a port fromsaid shoulder to said valve seat and being also provided with alongitudinal fuel supply port which dischargesl into the first namedport; and a plunger slidable in said bore of said cylinder and having anextension slidable in said reduced bore portion,` the lower end of saidextension being provided with a valve portion to coact with said valveseat when the plunger is fully lowered, said plunger having a downwardlyfacing shoulder above said upwardly facing shoulder of said cylinder andcooperable therewith in forming an expansible and contractible fuelchamber which receives fuel from the upper end of said iirst named portwhen the plunger ascends, the fuel being discharged from said chamberthrough said first named port and` through said fuel spray means whensaid plunger' descends. 4

6. An engine fuel injector comprising a tubular casing having a fuelsupply port opening through its lowered end, a cylindrical block havinga central bore of less diameter than the interior of said tubularcasing, the upper end of said block being disposed against the lower endof said tubular casing, said block being provided with an outerlongitudinal port and with an inner longitudinal port, the lower ends ofthese ports being in communication `with each other, the upper end ofsaid outer port being in communication with said fuel supply port ofsaid tubular casing,'the upper end of said inner port being open at theupper end of said block between` said central bore and the innerperiphery of said tubular casing; a ring having its upper side disposedagainst the lower end of said block. said ring having a central valveseat at the lower end of said central bore, said ring being formed witha fuel port from its upper side to said valve seat. the upper end ofsaid port being in communication with the lower end of said inner portof said block; a cap secured to said lower end of said tubular casingand containing said ring and'said block, said cap having fuel spraymeans open at said valve seat; and a plunger slidable in said tubularcasing and having a downwardextension slidable in said bore of saidblock, the lower end of said extension being provided with a valveportion to coact with said seat when the plunger is fully lowered, saidplunger having a shoulder disposed above said block and cooperable withthe u pper end of the latter in forming an expansible and contractiblefuel chamber which receives fuel from said inner port of said block whenthe plunger ascends, the fuel being discharged from said chamber throughsaid inner port of said block, through said port of said ring, andthrough said fuel spray means of saidcapwhen said plunger descends.

7. An engine fuel injector comprising a tubular casing having a fuelsupply port opening through its lower end; a cylindrical block having acent tral bore of less diameter than the interior of said tubularcasing,`th`e upper end of said block being disposed against the lowerend of said tubular casing and having an annular groove communicatingwith said fuel supply port, the vlower end of said block being formedwith substantially radial grooves, said block being provided with outerlongitudinal ports extending from said an-V nular groove to the outerends of said radial grooves and being provided also with innerlongitudinal ports from theinner ends of said radial grooves to theupper end of the block, the upper -tion with said inner'ports of saidblock; a cap secured to the lower end of'said tubular casing andcontaining said ringl and said block, said cap having fuel spray meansopen at said valve seat; and a plunger slidable in`said tubular casingand having a downward extension slidable in said bore of said block. thelower end of said extension being provided with a valve portion to coactwith said valve seat when the plunger is fully lowered, said plungerhaving a shoulder disposed over said block and cooperable with th upperend of the latter in forming an expansible and contractible fuel chamberwhich receives fuel from said inner ports of said block when the plungerascends, the fuel being discharged from said chamber through said innerports of said block, through said ports of said ring, and through saidfuel spray means of said cap when said plunger descends.

8. An engine fuel injector comprising a tubular casing having a fuelsupply port opening through its lower end; a cylindrical block having acentral bore of less diameter than the interior of said tubular casing,the upper end of said block being disposed against the lower end of saidtubular casing and having an annular groove communieating with said fuelsupply port; the lower end of said 'block being formed withsubstantially radial grooves. said block being provided with outerlongitudinal ports extending from said annular groove to the outer endsof said radial grooves and being provided also .with inner longitudinalports from the inner ends of said radial grooves to the upperend of saidblock, the upper ends of said inner ports'being disposed between saidbore of the block and the inner periphery of said tubular casing; a ringhaving its. upper side disposed against the lower end of said block,said upper side of said ring being provided with an annular groovecommunicating with said inner ports of said block, said ring having acentral valve seat and ports leading to this seat from said annulargroove of said ring, said valve seat being disposed at the lower end ofsaid bore of said block; a cap secured to the lower end of said tubularcasing and containing said ring and said block, said cap having fuelspray means open at said valve seat; and a plunger slidable in saidtubular casing and having an extension slidable in saidA bore of saidblock, the lower end of said extension being provided with a valve forcoaction with said valve seat whenthe plunger is fully lowered, saidplunger being provided with a shoulder over said block and cooperablewith the upper end of the latter in forming an expansible andcontractible fuel chamber which receives fuel from said inner ports ofsaid block when the plunger ascends, the fuel being discharged from saidchamber through said inner ports of said block, through said annulargroove and ports of said ring, and through said fuel spray means of saidcap when said plunger descends.

, JOHN W. DOW.

